17155055921 has 2 divisors, whose sum is σ = 17155055922. Its totient is φ = 17155055920.

The previous prime is 17155055909. The next prime is 17155055941. The reversal of 17155055921 is 12955055171.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15501495025 + 1653560896 = 124505^2 + 40664^2 .

It is a cyclic number.

It is not a de Polignac number, because 17155055921 - 2⁶ = 17155055857 is a prime.

It is not a weakly prime, because it can be changed into another prime (17155055941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8577527960 + 8577527961.

It is an arithmetic number, because the mean of its divisors is an integer number (8577527961).

Almost surely, 2^17155055921 is an apocalyptic number.

It is an amenable number.

17155055921 is a deficient number, since it is larger than the sum of its proper divisors (1).

17155055921 is an equidigital number, since it uses as much as digits as its factorization.

17155055921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 78750, while the sum is 41.

The spelling of 17155055921 in words is "seventeen billion, one hundred fifty-five million, fifty-five thousand, nine hundred twenty-one".